1. Technical Field
The present invention relates to a liquid ejecting head which includes a plurality of head bodies that eject liquid droplets and a fixation plate on which the plurality of head bodies are fixedly positioned, and a liquid ejecting apparatus which includes the liquid ejecting head.
2. Related Art
Liquid ejecting heads are known that eject liquid droplets through nozzles by means of pressure applied to liquid by pressure generating means such as piezoelectric elements and heat generating elements. Such liquid ejecting heads typically include ink jet recording heads that eject ink droplets.
JP-A-2005-096419 discloses, for example, an ink jet recording head (unit) including a plurality of head bodies each having a nozzle plate in which nozzle orifices are formed by drilling so that ink droplets are ejected through the nozzle orifices, and a flow channel forming substrate having pressure generating chambers that communicate with the nozzle orifices and flow channels such as reservoirs (communication sections) that communicate with the pressure generating chambers, and a fixation plate on which the plurality of head bodies are fixedly positioned.
In this configuration, the fixation plate is provided with exposure apertures so that the nozzle orifices of the respective head bodies are exposed therethrough. The exposure apertures are formed by stamping the fixation plate made of a metallic plate. Therefore, projections (so-called burrs) are produced, which protrude from one side of the fixation plate around the edges of the exposure aperture. Typically, the projections are formed to protrude toward the nozzle plate. This is because the projections may cause a problem in wiping the nozzle plate surface, if they protrude toward the target ejection medium, such as a recording sheet, which is arranged opposite the nozzle plate.
Moreover, the projections on the fixation plate are formed to engage with the metallic nozzle plate so as to provide electrical conduction between the projections and the nozzle plate, thereby allowing static electricity on the nozzle plate to be discharged via the fixation plate.
In terms of wiping the nozzle plate surface, larger exposure apertures are preferred. Specifically, the edges of each exposure aperture are preferably located outside the manifolds (reservoirs), which are formed in the flow channel forming substrate.
On the other hand, in terms of securely bonding the fixation plate and the head bodies, smaller exposure apertures are preferred in order to ensure a sufficient area for bonding of the fixation plate and the head bodies. Specifically, the edges of the exposure apertures are preferably located inside the manifolds (reservoirs), which are formed in the flow channel forming substrate.
Considering these balances, the edges of the exposure apertures need to be placed in the regions opposite the manifolds (reservoirs). That is, with the edges of the exposure apertures being disposed in the regions opposite the manifolds, it is possible to provide good wiping over the nozzle plate surface and ensure a sufficient bonding strength between the fixation plate and the head bodies.
However, in this configuration, a problem may occur in that the nozzle plate may be delaminated from the flow channel forming substrate during the manufacturing process. The manifold (communication section) formed in the flow channel forming substrate has a relatively wide space which communicates with a plurality of pressure generating chambers and has one side thereof formed by the nozzle plate. Accordingly, with the projections being formed on the fixation plate as mentioned above, the projections cause a force to be applied on the nozzle plate in the regions opposite the communication sections such that the force acts toward the inside of manifolds during bonding of the head bodies to the fixation plate, while they cause a force to be applied on the nozzle plate in the regions around the manifolds such that the force acts in the opposite direction. That is, a force acting in a direction in which it causes the nozzle plate to be delaminated from the flow channel forming substrate is applied on the nozzle plate outside the regions where they oppose the manifolds. As a result, the nozzle plate may be delaminated from the flow channel forming substrate.
In addition, even if the nozzle plate is not delaminated from the flow channel forming substrate during the manufacturing process, the nozzle plate may be gradually delaminated from the flow channel forming substrate after the completion of product, when the nozzle plate in the regions opposite the manifolds is continuously pushed by the projections.
It will be noted the abovementioned problems exist not only in the ink jet recording heads that eject ink droplets, but also in any liquid ejecting heads that eject liquid droplets other than ink droplets.